A disk in a disk drive is coated with a magnetic material which is magnetized with a write element (e.g. write coil) in order to write data onto the surface of the disk. Various influences may render portions of the disk surface defective. Such influences may include, for example, if the magnetic coating is not evenly applied to the disk surface or if a particle contaminates the magnetic coating.
During a defect scanning procedure performed by a disk drive manufacturer, the disk drive is connected to a test system and defective areas of the disk and certain areas adjacent the defective areas (i.e., unusable areas) are located and “mapped out” so that they are not used during normal operation of the disk drive. A conventional defect scanning procedure performed by a manufacturer typically involves sequentially writing and reading all of the tracks on the disk to identify defects on the disk. With current disk drives having disks with tens of thousands of tracks, the foregoing defect scanning procedure is very time consuming.